Analysis of Groundwater Contamination from Waste Dumpsites in Abeokuta, Ogun State

CHAPTER ONE

1.0 Introduction

Groundwater is one of the most important natural resources that supports domestic, agricultural, and industrial needs. In many developing countries, including Nigeria, it serves as the main source of drinking water because surface water sources are often polluted. However, improper waste disposal practices have increasingly threatened groundwater quality. Dumpsites located near residential areas allow leachate from decomposing waste to infiltrate the soil and contaminate underground aquifers.

Abeokuta, the capital of Ogun State, has experienced rapid urban growth and population expansion over the past two decades. Unfortunately, waste management has not kept pace with this growth. Most waste is disposed of in open dumps without proper lining or leachate control. According to Adebayo and Ojo (2021), many of these dumpsites are situated close to wells and boreholes used for domestic purposes. Assessing groundwater contamination from waste dumpsites in Abeokuta is essential for protecting public health and ensuring sustainable water management.

1.1 Background to the Study

Groundwater contamination occurs when pollutants from surface sources infiltrate through the soil and reach the water table. Common contaminants include heavy metals, nitrates, organic matter, and pathogens from decomposing waste. Once contamination occurs, it is often difficult and expensive to reverse. Therefore, prevention through proper waste management and environmental monitoring is more effective than remediation.

Abeokuta’s geology and hydrology make its groundwater particularly vulnerable to pollution. The city is underlain by basement complex rocks with thin soil layers that allow easy percolation of leachate. Ogunlana and Akinbile (2022) noted that most dumpsites in Abeokuta lack engineered liners, leading to the continuous seepage of pollutants into nearby wells and boreholes. Consequently, water users risk exposure to harmful substances that can cause diseases such as cholera, dysentery, and heavy metal poisoning.

Understanding the extent of groundwater contamination near dumpsites helps determine the safety of drinking water and supports environmental health management. This study, therefore, evaluates groundwater quality in areas surrounding waste dumpsites in Abeokuta and compares the results with national and international standards.

1.2 Statement of the Problem

Improper solid waste management is one of the leading environmental challenges in Nigeria. In Abeokuta, open dumping remains the most common method of waste disposal. These dumpsites are often located near residential zones, water bodies, and agricultural lands. During rainfall, leachate from decomposing waste seeps through the soil and contaminates groundwater sources. Residents who rely on hand-dug wells and boreholes unknowingly consume polluted water.

Despite increasing awareness about environmental health risks, regular groundwater monitoring around dumpsites is still inadequate. As a result, contamination continues to spread, affecting both urban and rural communities. This study seeks to analyze the extent of groundwater contamination from waste dumpsites in Abeokuta, Ogun State, and provide evidence-based recommendations for safer waste and water management practices.

1.3 Aim and Objectives of the Study

The main aim of this study is to analyze groundwater contamination from waste dumpsites in Abeokuta, Ogun State.

The specific objectives are to:

1. Identify major waste dumpsites located within Abeokuta and its environs.

2. Determine the physicochemical properties of groundwater samples around these dumpsites.

3. Compare the results with World Health Organization (WHO) and Nigerian water quality standards.

4. Recommend measures for minimizing groundwater contamination from waste disposal sites.

1.4 Research Questions

1. Where are the major waste dumpsites located in Abeokuta?

2. What are the physicochemical characteristics of groundwater near these dumpsites?

3. How do the measured parameters compare with WHO and national standards for drinking water?

4. What management strategies can reduce groundwater contamination in Abeokuta?

1.5 Significance of the Study

This study is significant because it provides scientific data on the impact of waste dumpsites on groundwater quality in Abeokuta. The findings will help local authorities and environmental agencies identify pollution hotspots and prioritize remediation efforts. In addition, the research supports Sustainable Development Goal (SDG) 6, which emphasizes access to clean water and sanitation, and SDG 3, which promotes good health and well-being.

Furthermore, the study will raise public awareness about the risks of using groundwater near dumpsites and the importance of proper waste management. It will also guide urban planners in selecting safe locations for future dumpsites and support policy decisions aimed at protecting groundwater resources.

1.6 Scope of the Study

The study focuses on selected waste dumpsites in Abeokuta, including Lafenwa, Iberekodo, and Kuto. Groundwater samples will be collected from wells and boreholes located within a one-kilometer radius of these dumpsites. Parameters such as pH, electrical conductivity, turbidity, total dissolved solids, and concentrations of heavy metals like lead, zinc, and cadmium will be analyzed. The study does not cover seasonal variations or microbial analysis due to time constraints.

1.7 Definition of Key Terms

• Groundwater: Water that exists beneath the earth’s surface within soil pores and rock fractures.

• Leachate: Liquid formed when rainwater percolates through waste material, dissolving contaminants.

• Dumpsite: An open area where waste materials are deposited without proper environmental protection.

• Contamination: The introduction of harmful substances into the environment, making it unsafe for use.

• Water Quality: The chemical, physical, and biological properties that determine water’s suitability for various uses.

References

Adebayo, T. J., & Ojo, K. A. (2021). Groundwater contamination from waste dumpsites in Southwestern Nigeria. Journal of Environmental Science and Pollution Control, 19(2), 44–59.
Ogunlana, M. F., & Akinbile, C. O. (2022). Impact of municipal solid waste on groundwater quality in Abeokuta, Ogun State. Nigerian Journal of Environmental Studies, 17(3), 101–117.
Sulaimon, A. R., & Olatunde, A. T. (2023). Assessment of leachate pollution and groundwater risk near urban dumpsites. Environmental Monitoring and Management Review, 15(1), 73–88.